The present invention relates to a device for feeding material to a mechanically or pneumatically operated substantially upright conveyor with a boom connected to a lower portion of the supporting frame for the upright conveyor, which boom is provided in the interior thereof with a conveyor and on the outside thereof with a rotatable material receiving tool which receives the material and transports it to the conveyor in the interior of the boom.
Such devices have the task to loosen the material to be transported from a heap and to take the material along and to feed it to the upright conveyor or in the region of the action of the latter, whereby the upright conveyor may be a suction tube, a bucket conveyor, a chain conveyor or a band conveyor provided with plates extending normal to the band spaced from each other in the direction of the latter to form a plurality of cells for receiving the material therebetween and in which the outer ends of the cells are closed by a cover band extending parallel to the band of the conveyor.
Such conveyor systems are known in the art and one known system comprises as material receiving tool a plurality of angularly displaced arms turnably mounted at the lower end of a substantially vertically extending suction transporting tube, in which the arms are provided with screw conveyors, which during their rotation pick up the material and transport it to the lower end of the suction tube conveyor (Deutsche Auslegungsschrift No. 21 05 143).
The German Offenlegungsschrift No. 21 49 647 discloses another system of the aforementioned kind in which in front of the suction nozzle of the upright suction tube conveyor at least one horizontally arranged rotating cutter spindle is provided which loosens the material and transports it towards the suction nozzle, whereby in order to increase the material transport a screw conveyor is arranged between the cutter spindle and the nozzle which collects the material loosened by the cutter spindle and transports the same to the suction nozzle.
Another system is also known in which the upright conveyor in form of a bucket conveyor is provided at its lower end with an axially extendable in a vertical plane tiltable boom provided with a movable scraper blade conveyor which loosens the material and transports it over a bottom plate or a trough to the buckets of the upright conveyor (Deutsche Auslegungsschrift No. 22 02 609, Deutsche Offenlegungsschrift No. 22 10 311).
Another system of the aforementioned kind is known from the German Auslegungsschrift No. 25 28 483, in which the bendable lower end portion of the suction tube of the upright conveyor is provided with a wide suction nozzle which is placed on a tractor and in which a scraper screw is arranged directly in front of the suction nozzle, which scraper screw is mounted on carrying arms connected to the tractor tiltably about its pivot axis, whereby the material loosened by the scraper screw is transported towards the suction nozzle.
All of the above-mentioned known systems have the disadvantage that the material receiving tools transport only a portion of the picked up material to the upright conveyor since part of the picked up material flows laterally away from the material loosening and transporting tools. This evidently detrimentally influences the output of the upright conveyor, respectively of the whole system.
The German No. 15 06 997 discloses further a conveyor system for unloading of ships in which loss of the material received by the loosing and transporting tools is avoided. In this known system, a tubular boom is mounted on the support frame of the upright conveyor in which at the free end of the boom a bucket wheel is mounted as a material receiving tool and in which the boom receives in its interior the offset section of the upright conveyor constituted by two transporting bands, whereby the material taken up by the bucket wheel is transported over a chute in its interior onto one of the transporting bands which is guided up to beneath the chute and transported by this one transporting band between the two transporting runs of the two bands of the upright conveyor. This arrangement includes further a shovel connected to the bottom of the wheel which during turning of the support for the upright conveyor picks up the material and pushes it into the acting region of the bucket wheel. This known system can, due to the relative small width of the bucket wheel, strip the material from a heap only with small cuts so that an extensive movement of the support of the upright conveyor is necessary if large material heaps have to be removed. If the support for the upright conveyor is not able, for some reason, to turn about its vertical axis, for instance, in the corner of the ship's loading space, the material can, in this case, not be received by the shovel and transported toward the bucket wheel.